The power-on sequence for a conventional digital camera typically requires numerous time-consuming operations that classically take many seconds to complete. This sequence of operations must be completed before the camera is ready to begin operations to take a picture. Most cameras on the market today have a power-on time that is greater than 3 seconds, and often is longer than that. Customers are often dissatisfied with the relatively slow power-on time of digital cameras. It would be desirable to have a method that dramatically reduces the length of time between the time when a user turns the camera on and the time when the first picture may be taken.
The power-on lag is very frustrating to camera users because they want to be able to recognize a photo opportunity, turn the camera on, and take the picture immediately. Often the power-on lag is long enough that the moment is lost and they have missed the opportunity to take the picture because the scene or something within it has changed.
In prior solutions, when a camera power-down indication is given by the power switch, the camera retracts the lens, then terminates all operation in internal processing systems. Power is shut off to all of the camera processing systems with the exception of a power switch monitoring component. This brings the camera to the lowest possible power consumption state.
A number of patents have issued that relate to waking-up computers and digital cameras from a low power state. For example, U.S. Pat. No. 6,308,278 discloses “Supplying standby voltage to memory and wakeup circuitry to wake a computer from a low power mode.”
U.S. Pat. No. 6,002,436 discloses a “Method and system for auto wake-up for time lapse image capture in an image capture unit.” It is stated in U.S. Pat. No. 6,002,436 that “A system and method for time-lapse capture according to the present invention comprises capturing a first image automatically; initiating a sleep mode after capturing the first image; and transitioning from the sleep mode into a wake mode prior to capturing a second image.”
U.S. Pat. No. 5,920,726 discloses a “System and method for managing power conditions within a digital camera device.” U.S. Pat. No. 5,920,726 discusses powering up a digital camera.
U.S. Pat. No. 6,031,964 discloses a “System and method for using a unified memory architecture to implement a digital camera device” and discusses “method steps for performing a power-up sequence” for the digital camera.
U.S. Pat. No. 6,282,665 discloses a “Method and apparatus to reduce power consumption on a bus” by “placing a node in a standby state.”
However, none of these patents specifically address apparatus or methods for use with a digital camera that reduces the time between camera power-on and the time when the first picture may be taken.